In the year since Dolly Parton's widely publicized crossover from the country genre to the MOR mainstream, the quality of her music has gone dramatically downhill while her fame vaults toward the tinsel regions of instant media celebrity. Actually, the quality hasn't gone downhill as much as it's disappeared completely. The only thing Parton's current output is good for is to be held up as a prop on television's late-night talk shows, and the only difference between her three mainstream albums is that each one seems to be worse than the last. If things go on like this any longer, the fact that she started as a great C&W artist won't even be in her biography but in Ripley's Believe It or Not.

When a singer with as much integrity as Parton apparently had makes a dramatic shift in style, you generally assume that the change was artistically necessary, even if the results aren't very encouraging. But Heartbreaker, like its immediate predecessors, doesn't even seem like an honest failure: it's flat-out, commercial schmaltz aimed straight at the Johnny Carson Show. The arrangements aren't as clean as good MOR — fat with horns, strings and synthesizers, the instruments sound like the Longines Symphony on angel dust — and Parton's voice, which could be sweetly innocent on her country records, is now merely saccharine, without the tough-minded, idiosyncratic individualism that once made the sweetness moving and powerful. The overstuffed, turgid settings are utterly at war with the clearheaded simplicity that was her musical trademark. Outside the stylized C&W framework, her voice and stance seem ludicrous, and the effect is to turn her into a fag-hag novelty act.

By the time you get to Dolly Parton's straight-faced duet with some syrup-voiced male vocalist on "We're Through Forever ('Til Tomorrow)," Heartbreaker has moved from the realms of lower-kitsch into something along the lines of a dead-singer joke. Parton once excelled at love songs — her heartbreak always had a prideful, determined edge, quite beyond the doleful resignation of most country laments — but even the best of her new material ("Baby I'm Burnin' ") is so insipid and complacent it makes "Have You Never Been Mellow" sound like "Shattered."

If Parton were just another showbiz example of "a dumb chick singer being manipulated by sinister forces from on high," everything would be a lot easier to explain. But on her C&W LPs, as a songwriter as well as an interpreter, she demonstrated an uncanny understanding of the idiom — an understanding that allowed her to broaden the field and make it her own without turning her back on its traditional forms. In all of country music, there's nothing quite like the sense of accelerating dread that propels Parton's great "Jolene." And My Tennessee Mountain Home, a concept album about her life until she became a C&W star, is not only a rare tour de force, but also one of the few really successful concept LPs I can think of in any genre.

On that record, as in all her best work, there's an economy of form, a deft precision of imagery, a sense of time and place that mark Dolly Parton as a major artist. It seems unlikely that such an intelligent woman would be so artistically uncertain off her own turf, but the other explanation — that she's a crass hustler, in it only for the big bucks and the gossip-magazine fame — is, for those who admire her early songs, even harder to accept. Parton doesn't act like a sellout as much as she acts like she's had a lobotomy. Even the Heartbreaker tunes she wrote herself emerge from a vacuum. They draw on the same ideas as her country material ("Nickels and Dimes," for instance, is a variation on the standard, poor-girl-makes-it theme), but don't have a shred of true feeling.

The biggest loss, however, is to Parton's dignity — a dignity that was once the backbone of her whole style, even in her occasionally cloying or gaudy moments. Now she's turned into a great American joke — a celeb windup doll — and that's exactly what she seems to want. It's strange, but the Dolly Parton who made Heartbreaker isn't only unrecognizable as an artist anymore — she's just marginally believable as a human being.